For your delight, here is the Sailfish (platform) SDK packaged as a docker image. However, at the moment you have to build it yourself, as I'm unsure about if I have the rights to upload it to docker hub.

While it seems that this has already been (done, especially by EvilJazz, but the plan here is a bit different: I don't package a build engine, but just the build tools. I hope that this can be useful for both app developers, and other platform SDK users like those using the HADK or doing packaging work.